Trial-frame optometer.



. I v v *y No. 791,808. K PATE-MED JUNE 6, 1905,

' J. C. MOALLISTER.

v TRIAL FRAMEOPTOMETER.

APPLIGAHON FILED 0012.22, 1903.

. UNI-TED STATES Patented June 6, 1905.

' PATENT OFFICE.

TRIAL-FRAME 'A OPTOMETER.

SPECIFICATION forming part of Letters PatentNo.' 791,808, dated. J'une6, 1905.

Application mea october' 22,1903.' serai No. 178,014..

.To a/ZZ whom it may concern:

j Be it known that I, JAMES COOK McALLIs- TER, a citizen of the UnitedStates, residing at Media, in the county of Delaware and State ofPennsylvania, have invented certain new and useful Improvements inTrial-Frame Optometers, of which the following is a specification.

My invention relates to an improved trialframe optometer in which aseries of lenses of different foci are. mounted upon a revoluble disk,so that each lens may bel brought consecutively before the eye of thepatient for the purpose of testing or examining the eyesight.

The object of my invention is to construct an optometer which may beused in connection with a trial-frame and vreadily placed in either rimof said trial-frame or shifted from one to the other of said rims.

A further object of my invention is to provide a diaphragm which will beheld between the patients eye and the lens-disk, so that but one lensmay be seen through the aperture in said diaphragm.V

A still further object is to, provide a handle by which the instrumentmay be held in its proper place on the trial-frame and more vreadilychanged from one to the other of the rims of said trial-frame.

A still further object of my invention is to construct a trial-framewhich is particularly adapted to receive said optometer.

Referring to the drawings, Figure 1 repre-I sents a front view of theoptometer resting in one of the runs of a trial-frame. F1g. 2 representsa rear view of the same. Fig. 3 is a sectional view as on line 3 3, Fig.2. Fig. 4:

is a front view of the optometer, showing a trial-frame particularlyconstructed to receive the optometer. Fig. 5 is a sectional view as online 5 5,` Fig. 4.

In the drawings, A representsfthe trial-J frame having rims A and A2,connected by a nose-piece A2. Attached to either rim is a temple a. Therims A and A2 are U shape in cross-section, as shown in Fig. 3.

-dle E, washers e being placed at either side of said handle to keep thesame from touching the disk D or diaphragm B. y

As shown in Fig. 2, the disk D is provided with depression d', arrangedadjacent to each lens. A spring F, having a projection f, is

secured to the diaphragm B, and when any one lens is brought intoalinement with the aperture 5 the projection f on the spring will enterthe depression 0l' and tend to keep the diskfrom revolving.

The optometer may readily be removed from the rim A2 by means of thehandle E and placed in the rim A, the handle E being turned to theopposite side of the optometer before the same is placed in the oppositerim, so that said handle will not touch the patients face. The diaphragmB may be rotated in the rim sufliciently to keep thev inner edge of thedisk D away from patients nose, as shown in Figs. l and 2.

Fig. 4: illustrates a trial-frame in which the diaphragms Gr and G aremade part of the trial-frame and the rims shown in Fig. 1 are vdispensedwith. A nose-piece g connects said diaphragms, and' temples g are alsoattached to said diaphragms.` Each diaphragm is provided with anaperture G2 and a slot g4, into which is inserted the pin C', as shownin Fig. 5. The pin C is provided with a nut C2. Suiiicient space is lefton the pin C between the nut C2 and the shoulder C2 to allow said pin tobe dropped into the slot g4g on the dia# phragms, so that the pincarrying the lens-disk may readily be changed from one diaphragm 7phragms are held rigidly, and it is therefore not necessary to use ahandle to steady the optometeras it is Where the diaphragm is simplydropped into the rims of the trialframe, as shown in Figs. 1 and 2.

Havingthus described my invention, Iclaim and desire to secure byLetters Patent- 1. In an optometer, the combination of a disk having aplurality of lenses, a diaphragm having an aperture formed therein, anda trialframe'adapted to hold said diaphragm, substantially as described.

2. In an optometerthecombination of a disk having a plurality of lenses,a diaphragm having an aperture formed therein, a trial-frame havingrims, a semicireular portion on said diaphragm adapted to fit into therims of said trial-frame, substantially as described.

3. The combination of a disk having a plurality of lenses, a pin uponwhich said disk is revolubly mounted, a trial-frame having diaphragms,and means of attaching said pin to said diaphragm so that said disk Willbe interchangeable, substantially as described.

4. The combination of a disk having a pluralitylof lenses, a pincarrying the` same, diaphragms forming a part of a trial-frame, saiddiaphragms being provided with slots to receive the pin carrying saiddisk, substantially as described.

5. In an optometer the combination of a disk having a plurality oflenses, a pin on which said disk is mounted, a diaphragm carrying saidpin and a handle loosely mounted on said pin, substantially asdescribed.

6. In an optometerthe combination of a diaphragm having an apertureformed therein, a pin carried by said diaphragm, a disk mounted on saidpin, a plurality of lenses carried by said disk, and a spring adapted tohold said disk in proper relation with the said diaphragm, substantiallyas described.

V7. In an optometer, the combination of adiaphragm having au apertureformed therein, a pin carried by said diaphragm, a disk mounted on saidpin, a plurality of lenses in said disk, a handle pivoted on said pin,washers on either side of said handle and a spring carried by saiddiaphragm adapted to bind against said disk, substantially as described.

In testimony whereof I afiix my signatu re in presence of two Witnesses.

JAMES COOK MCALLISTER.

Witnesses:

E. D. PATTERSON, F. H. VOODHEAD.

